Portable exercise devices have been a popular alternative to health club memberships for many fitness-minded people. The convenience of having an exercise machine in the home allows people to fit exercise into their schedules easily because they are not limited by health club schedules or inclement weather conditions.
One type of machine that has enjoyed increasing popularity is the abdominal exercise machine. Various forms of abdominal exercisers are currently available, the most common being a "rocker-type" apparatus that supports the head and neck while the user does abdominal crunches by raising the torso toward the knees. The rocker device has a generally U-shaped frame with a rocker portion and an armrest portion. A head support underneath the arch of the U-shaped frame cradles the user's head. To use the rocker device, a person lies on the floor on her back, places her head on the head support and her arms on the armrests, and bends her knees to reduce pressure on the lower back. As the user curls the upper body slowly upward toward the knees and back down to the floor, the rocker device moves along with the user to provide continuous support to the head and neck. In essence, the rocker prevents the user from pulling on the head and neck when doing abdominal crunches, minimizing the chances of neck strain from the exercise and requiring the user to focus on using only the abdominal muscles to lift the torso.
Rocker-type abdominal exercise machines, however, are limited because they can only be used to exercise the abdominal muscles and not other muscles in the body. Other types of equipment, such as home gyms, allow a user to exercise more muscle groups, but they tend to be bulky and expensive. Further, when using rocker-type machines or doing conventional sit-ups, the amount of resistance in the exercise is limited by the user's body weight. As a result, it is difficult to increase abdominal strength beyond a certain point without some form of additional resistance.
It is therefore an object of the invention to construct a compact, lightweight exercise device that can be used to exercise muscles in both the abdomen and the arms, shoulders, and back.
It is also an object of the invention to provide an exercise device that can provide additional resistance as the user's strength increases to allow further muscle development.